Car-brake.



PATENTED NOV. 6, 1966.

P.` H. ZEALAND. CAR BRAKE .LVPLIOLTIOH FILED IAB. 17, 1906.

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UNITED sTATEs PATENT OFFICE.

CAR-BRAKE.

Specification of Letters Patent.

Patented Nov. 6, 1906.

Application filed March la7, 1906. Serial No. 3063.571.

To all whom' it may concern.-

Beit known that I, THEODORE F. H. ZEA- LAND, a subject of the King ofGreat Britain, residing at Edgewood, in the county of Allegheny andState of Pennsylvania, have invented certain new and useful Im rovementsin Car-Brakes, of which the fol owing is a specification, referencebeing had therein to the accom anying drawings.

Car-bra re mechanism is usually so constructed that the maximum brakingor brakeshoe pressure has iixed relation to and is determined by theweight of the car when empty, this pressure, as a general rule, beingabout seventy per cent. of the wheel-pressure on the track when the caris light. A greater pressure would tend to lock the wheels and causethem to slide and flatten. It is obvious, however, that such maximumpressure is deficient for effectively braking a loaded orpartially-loaded car, and it is also clear that when loaded or partiallyloaded the wheels will lstand much greater pressure without sliding thanwhen the car is empty.

The purpose of this invention is to provide a variable braking ressure,which is determined automatical y by the weight of the car.

In the present embodiment of the invention I make use of powersuflicient for braking loaded or partially-loaded cars, and so applythat power that it exerts upward pressure on the car-body while beingtransmitted to the brake-shoes, the arrangement being such that thebraking pressure is regulated by the resistance of the car-body toupward movement. If that resistance is greater than can be overcome, thefull braking'power is transmitted to Athe brake-shoes, whereas if thepower is su'l'licient to lift the car-body a proportionately less amountof pressure is transmitted to the wheels.

In the accompanying drawings, Figure 1 is a top plan view, partly brokenaway, of a cartruck and brake mechanism having my invention appliedthereto. Fig. 2 is a vertical cross-sectional view on line 2 2 ofFig. 1. Fig. 3 is a top plan view of the spring-channel. Fig. 4 is adetail view of the mechanism for ransmitting upward pressure to thecarody.

Referring to the drawings, 2 designates the truckbolster, 3 thearch-bars, and 4 the spring channel 0r plank. 5 represents thebrake-beams 5 6, the brake-shoes; 7, the leverstrap, and 8 the deadbrake-lever fulcrumed thereto; 9, the live brake-lever, and l0 the guidetherefor, the parts thus enumerated being of usual or any preferredconstruction.

The braking power is transmitted to and through live lever 9, and inbrake mechanism of usual construction the lower ends of levers 9 and 8are positively connected. In apply-y ing my invention I provide ayielding or compensating connection for these levers, the movement orplay of this connection being dependent upon the amount of pressure t0be transmitted to the brake-shoes.

The lever connection, as here shown, consists of a head 11, having atone side arm 12, connected to dead lever 8, and at the opposite sideguide 13 for the plunger-like pushbar 14, the latter being connected tolive lever 9. 11 are the bell-crank levers 15, having their outer armsconnected to rods or links 16 and their inner arms disposed toward eachother and adapted to be engaged by plunger 14. Rods 16 extend toopposite sides of the truck and are connected to mechanism for exertingupward pressure on the car-body, the arrangement being such that whenthe carbody is lifted the rods move inward and the bell-cranks move orturn in response to the pressure of plunger 14.

In operation, power sufficient for properly braking the car when loadedis transmitted through live lever 9, such power being greatly in excessof that required and which can be safely used for the car when em ty.When the power is applied, the described connection between levers 9 and8 remains rigid unless it is sufficient to turn levers 15. With the carempty sufficient pressure is transmitted to the brake-beams for properlybraking the wheels, and the excess power is expended on levers 15, whichres ond to the pressure of plunger 14 and lift t e car-body. Theresistance of levers 15 is of course dependent upon the load, and thegreater their resistance the greater the power transmitted for brakingthe wheels. With the car fully or possibly only partially loaded levers15 remain fixed, and as the connection between levers 9 and 8 is thenositive the full power is transmitted to the rakes. Thus when applyingthe maximum braking power the amount thereof transmitted to the wheelsis determined by the load. It will of course be understood that theimproved mechanism may be so arranged as to remain inactive under lightapplications of the brake.

Fulcrumed in opposite sides of head IOO IIO

p The mechanism at each side of the truck for exerting upward pressureon the carbody is here shown consisting of two platelike lever devices17 and 18, mounted to rock vertically on ribs 19, formed on a plate 20,the latter resting on the spring-channel. The inner edge of plate 17overlaps late 18, and extending. downward from p ate 17, through anaperture in the Lspring-channel, is arm 21, to which the outer end ofrod or link 16 is connected. The outer portions of plates 17 and 18 haverocker-ribs 22 on their upper edges, which sup ort the spring-seat 23,on which rest the truc -springs 24. Thus it will be seen that an inwardpull on rod 16 tends to rock-plates 17 and 18, depressing theiroverlapping inner, portions and elevating their outer portions, therebylifting the spring-seat and trasmitting upward pressure through bolster2 to the car-body. Obviously the greater the load the greater theresistance of the rocker devices to the pull of rod 16.

While I have here shown and described my preferred embodiment of theseveral features of the improved brake mechanism, it

will be understood that the same may be diiferently constructed andvariously applied without departing from the invention.

I claim- 1. In a car-brake, the live and dead brakelevers, and mechanismadapted to exert upward pressure on the car-body, said-mechanism forminga compensating connection between the live and dead levers.

2. In a car-brake, brake-applying levers, mechanism movably connected toone of the levers for exerting upward pressure on the car-body, and anoperative connection between the other brake-applying lever and thesaid. car-lifting mechanism.

3. In a car-brake, two brake-applying levers, devices adapted to exertupward pressure on the car-body, levers connecting said devices with oneof the brake-levers, and an operative connection between said connectinglevers and the other brake-lever.

4. In a car-brake, two brake-applying levers, lever devices at oppositesides of the car Jfor exerting u ward pressure on the carbody, and twobe l-crank levers having their fulcrums connected to one of thebrakelevers, the other brake-lever being adapted to exert pressure onthe Jf'ree ends of the bellcranks. 5. In a car-brake, two brake-applyinglevers, lever devices at opposite sides of the car for exerting upwardpressure on the carbody, a head secured to one of the brakelevers,bell-crank levers fulcrumed in the 6o head and connected to the saidlever devices, and a device carried by the other brakelever for exertingpressure on the bell-cranks.

6. In a car-brake, a rocking car-body su port maintained normallydepressed by tie weight of the carbody, brake applying mechanism, and aconnection between said mechanism and the rocking support for raisingthe latter and regulating the pressure of the brake mechanism.

7. In a car-brake, a spring-channel, rocker devices operativelyconnected together and mounted on the channel and adapted to support theweight of the car, brake mechanism, and a connection between saidmechanism and one of the rocker devices for raising said devices andregulating the pressure of the brake mechanism.

8. In a car-brake, a spring-channel, overlapping rocker devices mountedon the channel, a plate resting on the overlapping rocker devices andadapted to be held normally vdepressed by the weight of the car-body,brake mechanism, and a connection between said mechanism and one oftherocker devices for raising the latter and regulating the pressure of thebrake mechanism.

9. In a car-brake, a spring-channel provided with roclrer-ribs, twooperatively-connected rocker devices mounted on said ribs, each of saiddevices having an upwardly-disposed bearing, a plate resting on said uwardly-disposed bearings and adapted to e held normally depressed by theweight of the car, brake mechanism, and a connection between saidmechanism and the rocker devices for raising the latter and regulatingthe pressure of the brake mechanism.

10. In a car-brake, a spring-channel, a pair of operatively-connectedrocker devices adjacent each end of the channel, said rocker devicesbeing adapted to be held normally depressed by the weight of the car, adownwardly-projecting arm carried by one member of each pair of saiddevices, two brakeapplying levers, two bell-crank levers carried by oneof the brake-levers and connected to said depending rocler-arms,andmeans whereby the other brake-lever is adapted to exert pressure on theJfree ends of the bellcrank levers.

In testimony whereof I aflix my signature in presence of two witnesses;

THEODORE F. H. ZEALAND.

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